1. Field of the Invention
This invention relates to structural systems such as buildings and the like and, more specifically, to the absorption of energy caused by the application of seismic and other forces to a building to thereby minimize the structural damage to such building.
2. Description of the Prior Art
Buildings of different configurations are typically comprised of vertical columns and horizontal floor beams coupled to the columns. Generally, the ends of the floor beams butt up against adjacent columns and are welded to the columns to secure the structural system in place in a rigid manner. This arrangement is satisfactory to absorb the energy from mild or small seismic shocks or forces exerted on the structural system: however, when such seismic shocks or forces are relatively large in magnitude, the structural system comprised of the columns and beams may suffer irreparable damage such that the structural system must be dismantled and rebuilt.
To minimize such structural damage, damping devices of different types have been used between the columns and beams to absorb some of the energy. However, such damping devices have not been completely satisfactory for one or more reasons, and improvements in energy absorbing means for structural systems of the type described is needed to provide a more positive means for absorbing seismic and other forces, such as forces due to blasts.
An energy absorbing device adapted to be coupled to a piping system or the like has been disclosed in U.S. Pat. No. 4,620,688. In this disclosure, a number of plate-like energy absorbing members of a bow tie or X-shaped configuration is provided. First ends of the energy absorbing members are coupled to a fixed support, such as a wall, and second ends of the members are cantilevered from the first ends, and an arm is coupled rigidly to the cantilevered ends of the element. The arm projects outwardly and has an end secured to one end of an elongated connector. The opposite end of the connector is coupled to a piping system or the like, the attachment point between the outer end of the arm and the connector being in a plane passing through the central or smallest regions of the energy absorbing members to minimize tension and compression in the members during displacement of the arm and thereby the cantilevered ends of the members themselves. Thus, the members will be substantially free of structural damage to buckling to provide a long, useful operating life for the members.
While the arrangement of elements in the foregoing disclosure is satisfactory for a number of structural applications, including piping systems and the like, it still can be improved upon when energy associated with relative movements of columns and beams of a structural system are to be absorbed.
The present invention provides such improvements because it provides for smaller deflections in building applications than in piping applications.